Book/Report

FZJ-2018-02680

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Bestimmung der Kinetik von Feststoff-Gas-Reaktionen in strömenden verdünnten Trägergasen durch Gasphasenmessungen

Pfeifer, J.-P. (Corresponding author)FZJ*

1986
Kernforschungsanlage Jülich, Verlag Jülich

Please use a persistent id in citations: http://hdl.handle.net/2128/18311

Report No.: Juel-2066

Abstract: Corrosion testing of high temperature alloys in flowing helium containing traces of chemically active gaseous components at very low partial pressures leads to experimental difficulties because the partial pressures can change significantly as a result of the gas-solid reactions. The reaction rates are then reduced. These changes in partial pressure, however, provide under suitable selected conditions detailed in-situ information on the kinetics and the mechanisms of the gas-solid reactions. Using gas phase measurements, the rates of heterogeneous corrosion processes can be directly determined. The detection sensitivity is extremely good. The lowest measurable material flow rates are around 10$^{-14}$ mol s$^{-1}$ cm$^{-2}$. The upper limit of the reaction rate is determined by gas phase diffusion. The diffusion transport is then only significantly faster than the surface reactions if the following equation applies: $\frac{dn}{dt} \frac{1}{A x} << 10^{-4}$ mol $s^{-1} cm^{-2}$ (dn/dt reaction rate, A reaction surface, x mole fraction of the gas component)

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Contributing Institute(s):

1. Publikationen vor 2000 (PRE-2000)

Research Program(s):

1. 899 - ohne Topic (POF3-899) (POF3-899)

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Database coverage:

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